The present invention relates to a sports treadmill, and more particularly, to a device with human effect in which the rotation speed of the motor can be automatically and synchronously changed in accordance with the running speed of the runner. Thc previous invention is provided with an automatic rolling band tied on the human body with the position of the band sensed by a sensor, thereafter, the detected value will be transmitted to a central processing unit (CPU) to obtain the exact information of the runner's position on the running belt in order to give an acceleration or a deceleration command and to achieve the expected effect. However, the runner will feel impractical and uncomfortable because he has to be tied by said band so that the use desire will be diminished and the effect of the installation of said band is lost.
Before describing the features of the present invention, a number of phenomena in jogging on the sports treadmill are briefly concluded as follows in order to understand the basic control principles of the present invention:
1. The position of the runner is kept unchanged when the running speed of the runner and the rotation speed of the running belt are the same.
2. The runner is shifted to the front side of the sports treadmill when the running speed of the runner is higher than the rotation speed of the running belt.
3. The runner is shifted to the rear side of the sports treadmill when the running speed of the runner is lower than the rotation speed of the running belt.
Therefore, the position of the runner will be changed in accordance with his running speed when he stands at the center of the sports treadmill to do jogging.